Please don't turn the silver filament tension knob on the Minis.  I keep finding them in the most loose position which can (and will) cause jamming issues.  I put notes on the printers to remind folks to not turn them.  They are reverse threaded in that left is tight and right is loose.  Please, if you don't know what you are doing, don't mess with the printers.  Send me an email instead.

Mini:

Some bad person left the tension knob at the most loose position (it is reverse threaded so right is loose and left is tight!).  Filament was all twisted around inside the print head.  After I took it apart and cleaned up the mess, it prints fine again.  

Mini #2: 

Had to adjust filament tension (another or same bad person messed it up) and then it printed a test print fine.

Prusa:   

Printed a test print fine

Taz 3:   

 All jammed up but I was able to heat the head and manually push some ABS through to push the jam out.  Ran a few feet of cleaning filament through the head then some ABS and then back to PLA.  It printed the fossil fish very nicely.

Taz 5:   

All jammed up but I was able to heat the head and pull the filament out with a good amount of force.  Ran a few feet of cleaning filament through the head then some ABS and then back to PLA.  It printed the fossil fish very nicely.  I had to spin the tiny head fan with a finger nail to get it running again.  I have a spare at home that I will install next week.